SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a41b1f2b1aff12aaec84646a9a46de2579b9795e8cfc129842fab361a02dc154' 
  AND token = 'RbNWRFxqwDl/4o0OylVNT398DUXNeINa7+L7xne0KT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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