SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56aedfe39b904a705e6720e2c8f549290d090f0bc79e60b154167438cc96fa06' 
  AND token = 'YrAIjny+br21QfxeGncXH7DBnhmhSzBLelUL8bt5DLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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