SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '127b1056d13e4237d42827c4b342a76534fa2b59977e2a4e94d373e33b549b6b' 
  AND token = 'GirKOkmpJNezZI9UB+0xxYLzA4c/Eljysv1eYja8KDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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