SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '27825fff01dbfad84e9d044a37419a876596ce5a2f6cf007725f013289671a74' 
  AND token = '6xS9JqUjOabh5O9lVBCCM6qI1zWkpUYDC9RL07rDJbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}