SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '681eab0a60a8e85619b39a0f1b25a2cf8c9e5056839b447d29b162996bb09911' 
  AND token = '0GKfRAmgehsYbPq1I4dykwCOZu46sbtkzQULVBbqB3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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