SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '887dd508fab341a415fc6a19a3eee55bb891c74667b4f2b87a69398fff8f6563' 
  AND token = 'R1dw4lnTHhdRnHwagb9s8rbxrMCfwQHMRdRk7kKSVTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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