SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1638596a97a610efcaf51dd413d7d4d435f5f85613a3539823c84c94a9fb6ca1' 
  AND token = '2No4tyI2WWcPI02n8C4LDbjMNtTt/pPY4b3kfmayBeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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