SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fa66f94447595c4a6d23dac144e409fbcb504c69330c59afdf513443a6cbf74' 
  AND token = 'A6+ptIrM4wd64PvLxpEocktyHGOptEkSzuKQklCQbLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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