SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f9cf05608a2a3c88201bc692ca3a50aa7cb4773bc5ed5f8acbf10bf29e30467' 
  AND token = 't6x064R3CwpOkfN7WaS/7UzZhGh6q9oQLU5+dJ8bfO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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