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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c903b16e42c18498268ed45e331fe8644c9714c416e6b997ee3cdac92fc1b8c' 
  AND token = 'Vf/HgcQ9lqPLJmCF4h2IiwCdMpEU2clHSw7VFj9oJ6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}