SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bee57159335ef602fbf3e014c7c0d8bac356db9a3f9853be8aee40ce0804509c' 
  AND token = 'lIUMjxkhVtyNuybd9FgbTAk43Co9YEOcptnfirslZcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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