SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b91d63091ddb3542f1cf7d9a4991c6eb2fb939d3139b40515290e9bbf1ebcd3' 
  AND token = 'Npzbdm1bWM1EQsjsFjOaY1cutorRUM+G6Ryxa387H9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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