SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2bd835dc6e2f304dad1b85721ac9184df39956d5eed664cf76968bda0ff69c97' 
  AND token = '5IiGWAhOBTsfMuHuuE7UqT6/cAiTMhXDyI0B6M6Ee5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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