SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc95faa03350587cefac8ad4ff4bb4e3dcdb94b7c9c5b181cec081e96fa2679' 
  AND token = 'nIRgJ/zjF9oD8zQyWkZY6eCVZlJHFRtdxnLqbSRlk/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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