SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93cc2347df0271f0d55767ce6746b99a7b0e2b52ddb741711b8f9c87e5ed6b2d' 
  AND token = 'CKKg1wzYCVmomT4tVxjrsHzyd1BsMbm9T/CLv8h78Rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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