SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '624fabaf5c48c9b90e2defa1e4768b5239cb7bb929dc392024b4dc8ec96be333' 
  AND token = 'NMoqDJJp/6u9jN0p5+lBTB4/LHAr/vqOWpxI1gP/wYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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