SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d19006107f8654a0a46be637f4bfb156bfd3ee6ca74c3e686aa1d49d690ce56' 
  AND token = 'Mgyebpxn2OX/6d42sAfa1NH5BIZ/u8m+EzbMLTzpQ5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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