SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '456e482f12301fe4e63113cb674a4a684585a15d2ff6fcdb903ea8efba93ad08' 
  AND token = 'JauxNIBHp/pFwUUsOS76oFmJkWZGgM3M29T0Yk5jQCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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