SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3ce6758ff69eddd7480dda2e2fc7c51d1cbe39ef079ba9b106d8a61ec01fcc3' 
  AND token = 'LSIZmJvMbn8PnKp3AzqwLoWsz94XmcyKRbhOlbdnakE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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