SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a293292d3436e4e46ab5908110d43ecabeb87f742137b934a88d27c6ca7dbe1d' 
  AND token = 'gOiHlv+P8RBn3OfCNMVA+wMI//XvcvTdO+UHcpnpI+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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