SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d31701f5e41f3523291f092ec8696bd1c730bb41c68736522e7a89fdd902d6c' 
  AND token = '/JDtAIdWl80CRU7K+ohvX/wXz24i7abSW4Gg21wZG4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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