SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c6962be358ae734d88cddb94c0381564f6bafa867be98071828d44d737156f0' 
  AND token = '9acWSbxGNHBzflIbG1XRvOMLRuReE6I5Is8kwCm9hV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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