SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec233f52629fe8b918fac3d9c22b245a14b38724b5b095e83cf7e4dc5d08f08d' 
  AND token = 'hKJg6Z+PgEg3BrphTPGCksFVU7AlsixgLjwMiCVO9i4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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