SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7786a44c3456b05733d3ae246acb8093612a72b30796a65c4a731d4db74246c' 
  AND token = 'VmlNBpQ9TJUVrswTHkTNQYQhxVWuw5kkwgSYj8Wdp78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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