SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d0b431b6eef9e4bb24ff917f9d0aa64b253c221d043a62835b79af39c517c9' 
  AND token = 'qhgjxlZ2i1TN7xR6FLzaBpYeyyFFZxPg03CrXAUzJ1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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