SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd06740044b625a54976351d88cc0034695f4adf9d50b1f2448496a46124ed776' 
  AND token = '0ANPoH7oemWz05BtXGHMnq91WzQhVUlETIaccz3BrmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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