SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bf6fac86a34f97a80ab8dbe47d23c2607b41ef170c8cf8fec864787b45e011f' 
  AND token = 'DfRZ0koRsLX5aHX8jlaxjDks0ZnTnzetcv/QwNrwtZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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