SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb25d59b7b1761db98c6cb0b95411488e7997c403e095c92ab16ad0d0389223e' 
  AND token = '3R/go1b3Dc/DsgAwZ94jg1gLipmMentjRmJuVUsIXHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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