SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6b7cc6fe124e3c87b56586e54eafe17a48e8830e4ff06ae7d327b7786bf80f5' 
  AND token = 'T7deBFMVTKlOpvyqhMza/hoz8LcUXLDv310TFe2V4YQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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