SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0683698eb64ec9b959be6aabdf15191389fd4c12b294173c730fdf973ccab9' 
  AND token = 'uTKWsSek4ueTQB2fe4/y2dlUiSvhXBQ6Ks+LcgM/9/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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