SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be2e7004bb458e3428454850eef67a7a24ea752522c36e1cbcd737aba7b65f14' 
  AND token = 'ZRC+xKvOVjIrEMEuLFF2z/sBINvggzkvp633LwbFsh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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