SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f1563ddc6811cd53f03657de7de8462f1359e6213f14d8ec000cbdf882d99e8' 
  AND token = 'bYrKYjePxjQppiISIQHMGXnPkytykLqlw2BuXrqFJ18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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