SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae041a57ad816c943a037b47abd89afc6d679629a39b1ed4002d7f0c058bc070' 
  AND token = 'SpawBjUpswFqZPvScnr6zmU9JvNgA/j44gUz6spxcSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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