SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c374d76074e94079e1ff4c37548c6c30420aeeef123a33ecf61b877c91331670' 
  AND token = 'tZ/TIyzUIaFJiIMpV5E6pFx0SyBltRILaMvs5b4a4a4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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