SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c38c6aa8a620881d0465b19d0a53bee7178aa3df867485d5cd8226893df535e' 
  AND token = '3n47gruhGYLOmVChSm1ZbsPUlrLHNHXQnJYOGh73vtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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