SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad6864d7beae98ffd0227eecaa8ad9c6b2f0740b0df34ce0691fc75131385013' 
  AND token = 'x0qprEXjYAPBlT/meCjcQ7KF3kyNvOIEwiWcirHNU5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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