SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f4b5526ffc9af7364f22ab35c8d0c72015561fa49870438178630718ccac8bf3' 
  AND token = 'Seo4YL6Gy/ldGusrZnwVd4xJNxs+z7DsUOzlOJ8SbRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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