SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fdab13fef85dea27bdda7172d6f3a1c8cb68f9a66d652fd245b3d8829fdff96' 
  AND token = 'ZXRLTR6Yn71aDpJg3i7Eb7/XFuRhAvVfSvjqta697+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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