SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0caa5046e65d0edf24b31917cddb53088b3a5f15f45e05a5998d3d8d4a164f' 
  AND token = 'xFnV0IyZTmZP6QHO53HMtg+Ve4ZYlUz5PrEXgm6S1gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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