SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '128dc22a176b7ced1ee56623cd6a13246453d2074523f36bd0c2d3e920670bf4' 
  AND token = 'MDVvEOaByqjbXlPyfLHeygK6Dj6OlSC7zvO2ufi/nO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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