SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3008d77323b31d904f13b7e13d8840eede9c12187a5e7c78678e430b277a896' 
  AND token = 'JUZs8R8nJsTdE4VmFaexqSXE8ZDXvBtsipmE6fCOgXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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