SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f6599c09881e496742b9d4d80527478434f4d5bc7b3a488f005ef83f3c05cc6' 
  AND token = 'QDa12RvhQwkwlj38eEodn2t+0XBQOiIVgpCUqODn/Ao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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