SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19c72d6a93c2e1becf1177e35115f8b04e0b1427499a1b3196ffd3ca4b9853eb' 
  AND token = 'RwR846LSycjJG6BZrKyJ0dheD+ILi6yauZvTfwcpAw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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