SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb0466c2749ee3bcc466fac3469825133986dab03245a8dbc0ea0f7ad9452128' 
  AND token = 'rTsup0f1SluQdMHwr7EnwKd1hjseL4bQnj7HCWyqI8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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