SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43608cb1cc9c758f3c9f794e4b40648a3f3381f5e35f05966e1112897e625250' 
  AND token = '9FrdpIZUj07ohiOvN02AYtpRB+hEvzYPKvRDF1jnmN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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