SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88545725ee010cfaeb472c308b9e7aed8dd21c7b06553afa35d71fa9d247fe18' 
  AND token = '61CHaDRfgeFqsnAb0cKXYuDrN9/pNGewOgu9h5LQ0eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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