SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b7227db07aae96b6a44fbcde5a95920cb3ccec5a2eacd1ba7b2d3b601e35e3' 
  AND token = 'InFwMPGBFwbSLsmoLubNl8lXS+lWFvtTapD4zsT1Xho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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