SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f399d7f10422fa39354974eefdc360c4bf0bdbed37872bb28621c34228a815d' 
  AND token = 'IqTMpTxBYxppnjnw/PmYwiw6RZLSK1Sw8GbmanTeKaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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