SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5695eefce8604f2956812e9b48ae0102ca711f639eae1295fa70c6160a5433a8' 
  AND token = 'b3bRxDWLHc4qyVHMBcyVVj0r8pf+gjFjC5YKJlRxhsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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