SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '49b3d000f254446800b66058eda5a1a6e40eed368b8fe2852207b2eeadcdeae2' 
  AND token = '0DtQsBLdgningKtJBu5ZoEC8rGaFNJo3jiwu9ZFF9vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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