SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd7513629b92484a7f9fd4b07c4d9358397d765bd4a3ed0b4c6a2f2b52dc13b2b' 
  AND token = 'RFpf6Br8HW+0JNbEQIV2afmqq/XmZhVvTooSSfI/11Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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