SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'deedf546cacd43792a898d84fc2ab202b5da3e28878dd3ff403c3c79440d3d65' 
  AND token = 'EVbgTlL6LZ6+6BZ1AOuqsyOeIctCsTXanNLNdC6g6kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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