SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e68f14e05734c409a2bab2de783f16c434c81a34618b662f8f53675bda5861bd' 
  AND token = 'lfoj/TYPT9fFx+GLO+vn0bysNgzqIPB4ZtqaBqTgyUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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