SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddca8fc8e4cc7501f89cdbdd18906c2d50761be0bec586a1541edc7ad4967882' 
  AND token = 'RZfHVV1oJywkBj6fMATLk0q5IFymlZ41NNSODe9eKL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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