SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97ecf1a69f10735e0670f8999315ee7dee6b3b068fc04ec6568cc33e7c228fb5' 
  AND token = 'JrQzKfS5tlSev2UMkosQB5mP+fwpkJCkxaqxpS5eFxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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