SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3db899b2645a432ef17d3b969f750c01795beb1f56be4994cb5fe0b515a12476' 
  AND token = 'AgfwVntORSWegVzfwPLhgo9ciWSY5Tis+ZkkpXDyITU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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