SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7769ff6f65d3bf4a2e5cafb02e1f726588d40916d828a9f5707be52bd11d8c51' 
  AND token = 'LTJOStivXfzQ9cl/VEf9hfsPMRjInkcCKgX/xKdMaCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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