SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '870d30f6600112c589ca78d9ff36c3c4d21d9b758500c52ee0a520e24c80eca4' 
  AND token = 'T7OchWGBDv7+ZMgjbfGwI9gDmsCEdPsrFmF3OGWx/+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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