SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cde53e04defb68ece2e0bca56594ed4de10465736f8196e6ce58c78c16c8154' 
  AND token = 'TkPIe6shiQas21ZHkdUZ/mSJDtzvtJIbkV0bfvE2fGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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