SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c6a3c8ef2d6b8bdf874ad24a7731cd2501d3186746afb76a08f06a5cb911264' 
  AND token = 'VCHSPR3dgjpvc7RnKF2M5h/66VxWUYG+IH4VSp2MTvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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