SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6b315f787e52897f5c8258aba65b36d76462c5277845f64ac2628a510e31d2ff' 
  AND token = 'Qb9O8alxgVaSUMrmJD4IzC+Hx7VQPY5t26k299ytdzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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