SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c466a030f2b7b49004ec17397c9da659d6af357a08cb29c9e1fdeb11edc39887' 
  AND token = '+cgyp9eF79nZMohcULfTnS85pSZfFmbt0SF3okfxMdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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