SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02a50f074291d0ae7bb7009ba2d0ff6f301c904a795857e85648f51da3cc8616' 
  AND token = '0PAe7hzWIB5zYnuEdZqd4/ISn14ipmMvxPrOiT7xzF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00198

JSON explain

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