SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1eb511c76eff68d8fde3baa942a3f4ce8b5be5590a16ec314e20d6a60381dca6' 
  AND token = 'KrTDAqXQu8FFIQJ2sBdugvT+2I8vxUvje3nVz5cYs4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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