SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54ce5f76b46503d439c3cbb247a095f880ddb4152e8cf48c451780a99df1520c' 
  AND token = 'oIZQ3ql9zGj6wytEVEtxFhw9fH6i/XpKBdBeeXI/190=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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