SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feaee554e8b5a7289ed88c719121bd3928937824867568465280cc1e383b8f74' 
  AND token = 'z3YCuMYkHBScds+OLccssa1oGxbkPYmBjDgk9FV+lCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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