SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a910babccb99570c594e727155eb4c631f375cd24fb3379b78715b42b15cd3b1' 
  AND token = 'HRAXJmQ/I+2UPkuWILz4dOE4J9hhwAsuKF5gmazbfIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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