SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3d123de23c340655b1694f033c14973e822f1477e60100c66a50d52c66e8d3' 
  AND token = '1tL1vetuPQeQsbapCC5zi3nmVlwNL3pXqPv2F4DaPEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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