SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11e7209b317ec50dc7fe37783cbfa2ad900d8cb550979dbfdb281a77512bbbc7' 
  AND token = 'pLSNOCPBOuOFYWgCOCKywVzqoRDzWL7NZQ4WovpMJWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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