SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c177a15e2c89d06bf01031af7f5ea72c867159bd19b6facd33bc7a3f211e7199' 
  AND token = 'QnMsidDnfwiEMkB2LqNvQ1CggVL7eOz84rIuKQ2iSjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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