SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5b9c54325eb3a8c30f74d2c2b985d1eeca643570c46d2d217a8589b9c1a861' 
  AND token = 'fyvdXiosw1rqYLkroZxMCFTxNhRDP2oJZniKdnEYkaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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