SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e69fcc6be1e9887bebb585d3ea8704b7af832d58bbf50e4f7ed71de3b5cc863e' 
  AND token = 'B38US+n57P1HvGhS2MOGG2cHCXi3p+lOX4eCGUaAGhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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