SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40e84880ef5b6aaf3f90f35d8535aee1f8f2610244a61bd858ad273bc4e2a947' 
  AND token = 'G1R5i3ZANBeleVj6uKu0wWd2eoZzGChSKn6FSwmyovY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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