SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbe9a19b74911f4d770b83b3f21340683e1d68ad162882c8062b463752e3ec8' 
  AND token = '6W5WkzUqp/3mmlGwjnvgaZ2VIqUolPsY5YnnQTl8qsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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