SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '330972f6ba7fdd57ec8ffbdb92d93acf3f6512552f26ebd980c68a7c6cb65964' 
  AND token = 'ISokffXaeVydwZl93pr9td9i9VRmjJL11i3KAJhvq7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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