SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d8d77ecd1f7dab80fdf4b25b17d0d52f828ecd1297678f8f515deb215491361' 
  AND token = 't897bXqZjnh9xtySI2DHTTB2L7+0AW5wBSjkQv1Gbf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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