SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a192ad82e0b051c2f64713e420667c7b135eaaa38fd0c908627b46ea95cfa21' 
  AND token = 'VbD6HrYacKIUvW9BXUW4rBRqrVpSmrli5uYKuCv9HBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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