SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c329318417179f530b0f02540eba0de4b1b4be52a24add4dd8017210cc6176e' 
  AND token = 'DSoYZI+ANRC6RusvqUAvdr46jdj5jCoVwnbxvYZffJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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