SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1df6ff6eee16ffe21bcf41f12b321912986a97305278546dcd2a0fe383f86f2e' 
  AND token = 'TNcRdlCTNaoEN8NHUJox3jC1KBH6m7VpblzJKVQeVDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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