SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0e5b2034a1694612a270b30149da94b0ec7fa8160c88924d093510e7434bfa' 
  AND token = 'ARQnOLZDl5xGtgZwuo6yz+wk1rCW3Pv3J7CAwFYiS84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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