SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4489e139ab4d4fd40bd7c9f1663e93433cc79a47b9e3f549c946e21ced749507' 
  AND token = '9kBgsBTRuPOiZkaMDSo1rN1m3VEfmXK7eLSzuA6U0XY=' 
  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"
    }
  }
}