SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1e800b794a87a718a2d6efb590757be2d1e5ce64738d526f1c201139113f6d2b' 
  AND token = 'mELQh7Szbn/FRigKTtZEcQfPWYJUa3G0+CR5iQsjwOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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