SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a85b0f0a15c4de3dc4c3e74191423d994ba08a7d5cca583caba862549956ac69' 
  AND token = 'Nl8npu/+uO9fQP1k4NXzRF6C4FtXWtEt/jGqd7QF2dA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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