SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85e31821e1da6257828f405cba0c56bfa49e22e559e8050d6c01a4a2247b97ca' 
  AND token = 'IrPxhTPBj4gq/fJMfk3wQiF4+1K0A7Zi/sF1zQGcYgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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