SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a7a14a43e96f790d5aace1edef000442a6bb4a4239537f6547e97ed6d4d6ba7' 
  AND token = 'ceRnU7wKosXNypUSJArShY20XQrmRL14QbFqfy+mBS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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