SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89e66f2def01c495197076df728bafafa17c0cedd90b9860fc4619e64657a7e0' 
  AND token = 'so9R84QDc0+D/DkcmaZN8tutOjmGj6EX9Xmymmqb7xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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