SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '488eb6e537daec5252774f50b77cff53a8a85164287e4c3e34e75fdc1d7b9a28' 
  AND token = 'iRMW/l55C+eonik3Q+K+nnCC486hIWXbGgKAXcFlqi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}