SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8dec998c3449ce0e077ddf8a4a288320596573ab026076c47574c2afb4a279c' 
  AND token = 'qHnok1HhbiGodU9XbTQcfkQnxY15piwDWinXYOV14+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}