SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '494b9bd2cb27cb5fe3b6014a27ff33d48136f9caa14813f0122e582543d9897b' 
  AND token = 'QY+mlYHn3onMkKx5gjzoMTx0NiBYeYZaaWlLDZulsX8=' 
  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"
    }
  }
}