SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89be82e4688629c91a0b2c61801ae440bd22251d6f7dcf6c77ebbd363f4ea3dc' 
  AND token = 'kBap6GPjW0WvnFpnfv9a+ovVHhfTCfUYTDXn/KMFbhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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