SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1fe61494157e0b7fb1d348f4c68eb718ef7e23758152e579225f121ed5d6854' 
  AND token = 'W804eJ4g9Lxt8T9zqEmiCZeBdsVpRKyGw/yBjPq1QZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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