SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ed5ce082664980268e078870ac55fffc64f93171266c337bf3a561c23a52fcf' 
  AND token = 'KgZ/gmIiJmNk2fRLoztpGjCp2UDx47UQZ2L+iky86iU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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