SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c124d984bdd1a5f244204e2a20efcac8d45974caf735e70fed46329e9915d418' 
  AND token = 'bhPhxTm4tDuLFcoLj5nWZXoEGP8hjIexpjaLpv7/bz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}