SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '72d9de2070f5826a03775f8a48d4d8b7c45498ddef0ac0d19d8e9ec675ca1a5f' 
  AND token = 'iYYhKYieaDa4IY3BKDLSeeMy+skCb2WSjVxSz/tbX2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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