SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee93056dae3956f6198d200637b60ffaba2c3c6157b5e12d730e94c4c573fc30' 
  AND token = 'qxgMJVHyU9OnoOe8D5QcoNh94bYljLGSwqACboQQOPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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