SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99807e05166cb1cf4a427c16f1705a34664b822640c5af622ba775c5c87f5d65' 
  AND token = 'WxVyXsRmuHlSrt1vl5YREuLxOPLGl/+kUf7nradjoPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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