SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8021df276df32c18f3be8b9b800365baeb94ca7b80a8e957b301793e1f83e87c' 
  AND token = 'vt8JEAE0RcuEN6NuH0z3sN5a09AwzxsRVqiZpFFripE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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