SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec0e19a0629d112f072678972f7d8dc9f3137b5943ea723f1178b7361a21d34e' 
  AND token = 'lpzKdQe7cbnAZ9rc/mpHyLyx0V4xrozKA3fp/Ge/7d0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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