SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fcc446eff7b1dbbb58d742cb9b7af0f5a1e628906b467a0938210f90cd7ca37' 
  AND token = 'tZqYXBTMXKLvFFBDnWnrXK3QhswMHk0vau2FSw0CtyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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