SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589563b0d9138452d0a5dc7fe58bfb3c0ef08aa71058e657acc519e1dd14e774' 
  AND token = 'PlHjx6SI6tBksFai9TDkfsncm6QsHCDwIeB6EE239T8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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