SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e74ae6dc2217424cc1fdc121ddd6802e9a135a6400fccbf53ca80ea834e1179b' 
  AND token = 'qRKy9OHhD/qwD8cUKexHd1MTZkY9yEHGgNJOrIgwkBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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