SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5b124378c3e483f403e07f091f7d93a16ff83650df3ca7900417bf646fd8e54' 
  AND token = 'TMJuVw5RB1HirRrIwi1C/GqmKQ0J6pH/csTnYGZnvXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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