SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b8e8b597554413824a1a2994b1f5ee4c0875ee8bed50019322968626c0f5305' 
  AND token = '1NqlSEVpyOnVAw7ru7uekR3Iw+IvPIgXVCI+WUDFgGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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