SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2daf06fdfa76381a7dad578a21dfbf85308b564a0f4c8eabf41dbe6749143afc' 
  AND token = 'FQwfV3vQLh8XpCYoUr1xF9zOHh6cFXcOuh+vJb/V4EY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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