SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cfaad5f27d4cf899a107772b2ce353a919d70b422bc8f89571ed3885f4cf7e4' 
  AND token = 'l7nlrKjwavXtgAKJXyOLM6nuuF1mcy9Mrqy+p6bfuLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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