SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4d4a5365b7be7a4e50f94103e7a4f9a7cad3f9048cb8907267702f83a5eb70f' 
  AND token = '57gROC3v/b2pQxdC4I03qh2B3usdLDSYBStyAxZVp0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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