SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bab808a7ce9e42cd6bcd9c5e25d103c50ce1df63d8571d19120fc664e634938' 
  AND token = 'arCgPI8Q5DLn7abMd1O7ecB0US1RUvtutziDbzlHrpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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