SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a13c87e1a90f82c49dd0b6ecc5b6518518b49e7a2018eb0385bc44b8634587d7' 
  AND token = '/+rjp3QXJI2jyIoiFfF/qRQv1D7ZTWY8qU+XK6vqEO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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